Neighbors said they heard a crash and ran outside to find a Japanese-made motorcycle against a tree and the rider, a young man, on the ground unresponsive. According to scanner reports, the accident occurred shortly before 7 p.m.

Patrick Jones said he found the man's cellphone and used it to call the first number, which turned out to be the victim's wife. He said he told her to go to UMass Memorial Medical Center — University Campus in Worcester, where the man was being taken.

"My sister (Lyndsay Jones) and our neighbor Ray (Raymond Desilets) were doing CPR," Mr. Jones said. "One of the people who stopped was a nurse."

Mr. Jones said the motorcyclist was wearing a helmet when they found him.

A police dispatcher Monday night said officers were investigating a crash in town but could not provide any further information.

At the scene nearly an hour after the accident, a motorcycle could be seen lying against a tree on a curve and accident reconstruction specialists worked at the scene.